Underwater ducted turbine

Abstract

An apparatus is disclosed for a turbine for generating electrical power from water or air flow comprising at least one rotor disk having a plurality of hydrofoil blades, a guide vanes, a cylindrical housing, and a generator means. A rim generator comprising a magnet race rotor rim and fixed stator coils in the housing is used. The apparatus is fitted with a screen to stop the ingress of debris and marine life, and a skirt augmenter device to reduce the Betz effect. The apparatus is preferably for sub-sea deployment and driven by tidal currents, but may be powered by river current or wave driven air or by wind. The apparatus may be deployed on at least one telescoping pole, tethered to the sea-bed and kept buoyant by buoyant concrete in the housing, inserted in a dam, under a barge or in a tidal power array.

Description

1. TECHNICAL FIELD[0001]The present invention relates generally to hydrokinetic electrical power generating turbines and methods of use and deployment. More specifically, a ducted rim type generator, bi-directional turbine for generating power from tidal currents in various deployments is disclosed.2. BACKGROUND OF THE INVENTION[0002]Tidal power has been harnessed for many centuries. Tidal grain mills have been located on coastal inlets where seawater could be trapped by sluice gates in low dams at high tide, to be released through a mill wheel at low tide. Such mill wheels are examples of rudimentary hydraulic turbines.[0003]Energy shortages have spurred research activity, including the construction of significant pilot projects in the area of tidal power generation using more modern turbine designs, in Normandy, France and Nova Scotia, Canada. The Normandy and Nova Scotia projects required significant infrastructure and damning of tidal estuaries. The effect of all such projects o...

AI Technical Summary

Benefits of technology

"The present invention provides an improved hydro turbine generator that overcomes disadvantages of prior art. It includes a hub parallel to the water flow, blades, a cylindrical housing, and guide vanes that redirect the water flow to strike the blades at an optimal angle. The vanes may be fixed or flip between a first and second position to minimize downstream efficiency losses. The invention also includes a bi-directional turbine with dual counter-rotating rotor disks to create a stable, efficient turbine generator unit minimizing swirl losses. A screen prevents marine life and debris from entering the turbine unit. A longitudinal hole in the hub allows water to flow through. An augmentor skirt minimizes the Betz effect and is adapted to rotate the guide vanes when the water flow changes direction due to the tide change. The invention also includes a rim generating hydro turbine where the generator is flooded with ambient fluid. The hydro turbine generator may be deployed individually or in any number of units, and may be used in various locations such as pylons, under a raft, tethered to the marine floor, or floating due to an integral buoyant structure."

Problems solved by technology

The Normandy and Nova Scotia projects required significant infrastructure and damning of tidal estuaries.

The effect of all such projects on the ocean inlet and estuaries is to interfere with tidal dynamics and disrupt marine biological ecosystems in the inter-tidal zones behind the dam.

While the pilot projects in Normandy and Nova Scotia are still in operation, they have not proven to be economical, and with the global rise in environmental consciousness, this approach has fallen into disfavor.

It is very difficult to maintain the integrity of water seal in a hydraulic turbine, as underwater turbines are subject to high levels of vibration, erosion and torsion due to the density and velocity of the water.

The trash screen of the Mouton patent protected only one end of the turbine and was not self-cleaning, requiring constant regular maintenance.

The current technology for hydro turbines is unsatisfactory due to the large number of moving parts and complexity of manufacturing, installing and maintaining turbines in the corrosive salt water environment.

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